28140780 has 96 divisors (see below), whose sum is σ = 85349376. Its totient is φ = 6900736.

The previous prime is 28140743. The next prime is 28140781. The reversal of 28140780 is 8704182.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (28140781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47647 + ... + 48233.

It is an arithmetic number, because the mean of its divisors is an integer number (889056).

Almost surely, 2^28140780 is an apocalyptic number.

28140780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28140780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42674688).

28140780 is an abundant number, since it is smaller than the sum of its proper divisors (57208596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28140780 is a wasteful number, since it uses less digits than its factorization.

28140780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 28140780 is about 5304.7884029431. The cubic root of 28140780 is about 304.1669644917.

It can be divided in two parts, 28140 and 780, that added together give a triangular number (28920 = T₂₄₀).

The spelling of 28140780 in words is "twenty-eight million, one hundred forty thousand, seven hundred eighty".